This article was originally published in the May/June 1993 issue of Home Energy Magazine. Some formatting inconsistencies may be evident in older archive content.

| Back to Contents Page | Home Energy Index | About Home Energy |
| Home Energy Home Page | Back Issues of Home Energy |

Home Energy Magazine Online May/June 1993

TRENDS IN ENERGY

Trends in Energy is a bulletin of residential energy conservation issues. It covers items ranging from the latest policy issues to the newest energy technologies. If you have items that would be of interest, please send them to: Trends Department, Home Energy, 2124 Kittredge St., No. 95, Berkeley, CA 94704.

Outdoor Lighting Savings

There are many small demonstrations of the appreciable savings to be reaped by replacing incandescents with fluorescents. The well-known rule is to replace first those lights used most, and this frequently means outside lights. One must be careful because not all fluorescents are suitable for outside use. Our experience with an outdoor lighting retrofit at Coventry, a small townhouse complex in Chapel Hill, North Carolina, with 43 units, was a positive one.

The road and parking area at Coventry was completed about eight years ago and the builder provided 13 colonial-type hurricane fixtures for the parking area. Each used a 100W incandescent bulb. A poor set-up, but typical at that time. In retrospect both our builder at Coventry and the Town of Chapel Hill should have set higher standards for lighting. We finally decided to try several fluorescents in December 1990. We chose 18W lamps with electronic ballasts and hoped they would cast as many lumens as the 100W incandescents. Finally, in August 1992 (things move slowly in the South) we replaced the remaining incandescents with fluorescent lights. We could then compare our Duke Power lighting bill for the September 1990-December 1990 period of incandescent lighting to the September 1992-December 1992 period of fluorescent lighting (see Table 1).

Savings during the summer months when the period of lighting is shorter should be less, but it is a reasonable estimate that we can save an average of $20 per month year round. Our 13 fluorescent lamps cost $231 and are estimated to last more than two years. Some may last much longer. Incandescent bulbs cost much less, but the experts tell us that we would replace each incandescent 10 times as often. We also save the inconvenience of replacing incandescents every few months. Our payback period is less than a year. They are still lighting our parking area, saving money, and helping the environment. Our savings at Coventry are no big deal, but they do illustrate the possibility of large energy savings if other condo and townhouse home-owner associations would follow suit.

-- Arthur V. Dodd

Arthur Dodd is a retired professor of geography at the University of North Carolina at Chapel Hill.

Table 1. Savings from installation of energy-efficient lighting in parking area Savings (1990 versus 1992)
Month $ kWh1
________________________________________________
September 21 323
October 23 354
November 24 368
December 26 396
________________________________________________
Total 94 1,441
________________________________________________
1. Based on a billing rate of 6.5cents per kWh up to 350 kWh per month, and 7cents per kWh over 350 kWh per month.

| Back to Contents Page | Home Energy Index | About Home Energy |
| Home Energy Home Page | Back Issues of Home Energy |